Briefcase



FIG. 1 is a top, front, right perspective view of a briefcase showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is a top plan view thereof. 

The ornamental design for a briefcase, as shown and described. 